USB connections

Is there any way to lock in my USB controllers to a specific peripheral.
I have a mix of 8 x USB and 2 x USB2 controllers and when writing to my external HDD throughput is very slow some times. Presumably the cause is random selection of USB or USB2 controller.
I have disabled some USB controllers but then cannot always connect to printer and/or CD drive.

No, there is no way I know of to lock a specific USB controller to a particular peripheral.

All of your USB ports should be a USB 2.0 protocol, but if you have an external device that is USB 1.1 only, then all the ports on that link default to USB 1.1 speed if I'm not mistaken.

You are not mistaken